Background: About 20% of patients who develop left ventricular (LV) systolic dysfunction will have improvement in ejection fraction (LVEF) over time. This patient cohort is generally excluded from large sudden death trials and, hence, understudied.
Purpose: To evaluate the predictors of mortality in patients with severe LV systolic dysfunction who have improvement in LVEF during follow-up.
Methods: Patients who had transient LV systolic dysfunction from 2010 to 2014 within the Aurora Health Care system and who had LVEF improve to ≥ 40%, irrespective of implantable cardioverter-defibrillator (ICD) implant, were studied. Predictors of mortality were identified using Cox proportional hazards model. Patients were then divided into groups based on LVEF > 50% or < 50% to assess for benefit of ICD using Kaplan-Meier estimates.
Results: A total of 1,364 patients met inclusion criteria; 58.4% were male, and mean BMI was 29 ± 7. Mean age post-LVEF improvement was 66 ± 14 years, and with each added year the hazard rate increased by 5% (hazard ratio [HR]: 1.05, P < 0.0001). Several clinical characteristics emerged as predictors of mortality, including smoking (HR: 1.8, P = 0.0002), chronic renal disease (HR: 2.3, P < 0.0001), atrial fibrillation (HR: 1.4, P = 0.013) and no-ICD (HR: 2.1, P = 0.012). With each percentage increase in LVEF, hazard rate decreased by 2% (HR: 0.97, P = 0.007). However, presence of ICD did not significantly improve mortality in the group with LVEF > 50% (P = 0.2), whereas it continued to show benefit in the group with LVEF of 40%–49% (P = 0.001).
Conclusion: Clinical predictors of mortality in patients with transient LV systolic dysfunction may help further risk-stratify this cohort of patients. It appears that patients with LVEF of 40%–49% continue to derive benefit from ICD therapy.